1. Field of the Invention
The present invention relates to a cassette type stapler and more particularly to a cassette suitable for use in large-sized staplers which are utilized to bind a great number of documents.
2. Description of the Prior Art
There is known a cassette type stapler comprising a base member, a cassette mounting member pivotally mounted on the base member and a handle member pivotally mounted on the cassette mounting member, the handle member including a driving blade which is located thereon substantially at the forward end of the handle member. In such a stapler, a certain cassette can contain only one type of staples. With a so-called heavy-duty stapler known in the art and if it is found that staples charged in the heavy-duty stapler are not suitable for use in the thickness of sheets to be bound, a cassette containing such staples is removed from the stapler and another cassette containing staples suitable for the set of sheets to be bound is then charged into the stapler to bind this set of sheets. On completion of the binding and when it is wanted to bind another set of sheets having a different thickness, the previously used and remaining staples should be removed from the stapler and still another staples of a further different size should then be charged into the stapler. Thus, such removal and charge of staples would be repeated for various different thicknesses of sheet set to be bound. At this time, it is possible that the temporarily connected staples are disintegrated and that the disintegrated staples result in injury to the finger(s) of an operator. In any event, the exchange of staples in the prior art staplers was cumbersome.